1. Field of the Invention
The present invention generally relates to a liquid crystal display panel, and more particularly, to a multi-domain vertical alignment (MVA) liquid crystal display panel.
2. Description of Related Art
With such advantages as high image quality, high space utility rate, low power consumption and free radiation, the thin film transistor liquid crystal display (TFT LCD) has become a major product in the display market. Current requirements for performance of the LCD are directed to high contrast ratio, fast response and wide-view angle. For example, a multi-domain vertical alignment (MVA) LCD can achieve the requirement for wide-view angle, which is described as follows.
FIG. 1 shows a top view of a conventional multi-domain vertical alignment LCD, wherein only one pixel is illustrated. FIG. 1A shows a cross-sectional view along line A-A′ in FIG. 1. Referring to FIG. 1 and FIG. 1A, a MVA LCD panel 100 at least comprises an active-device-array substrate 110, a color filter substrate 120 and a liquid crystal layer 130, wherein the active-device-array substrate 110 at least comprises a substrate 111, a scan line 112, a signal line 113, a common electrode 114, a thin film transistor 115 and a pixel electrode layer 116. More, slits are formed in the pixel electrode 116.
In addition, the scan line 112 and the signal line 113 define a pixel area 110a on the substrate 111, wherein the thin film transistor 115 is disposed inside the pixel area 110a and electrically connected to corresponding signal line 113 and scan line 112. The pixel electrode layer 116 is correspondingly disposed inside the pixel area 110a and electrically connected to the corresponding thin film transistor 115. The common electrode 114 and the pixel electrode layer 116 serve as two electrodes of a storage capacitor.
Referring to FIG. 1 and FIG. 1A, the color filter substrate 120 is disposed over the active-device-array substrate 110 and at least comprises a substrate 121, a color photo-resist layer 122, an electrode layer 123 and a protrusion 124. In addition, the color photo-resist layer 122 is disposed on the substrate 121, the electrode layer 123 is disposed on the color photo-resist layer 122 and the protrusion 124 is disposed on the electrode layer 123. Besides, the liquid crystal layer 130 is disposed between the active-device-array substrate 110 and the color filter substrate 120, wherein the liquid crystal layer 130 comprises a plurality of liquid molecules.
When a driven voltage is applied between these two substrates 110 and 120, electrical lines near the slit 118 in the active-device-array substrate 110 and the protrusion 124 disposed on the color filter substrate 120 are distorted and thus alter the alignment of liquid molecules near the slit 118 and the protrusion 124. Therefore, a LCD with a wide-view angle is fabricated by means of the different liquid crystal alignment. However, aforementioned design of pixel structure has several problems when displaying moving pictures, which are described as follows.
FIGS. 2A and 2B are schematic diagrams of checking the display quality of a conventional MVA LCD panel by using moving checking frames. FIG. 3 is a top view of a liquid crystal molecule alignment state. Referring to FIGS. 2A, 2B and 3, first, a black block 210 is displayed on a white frame 220 as shown in FIG. 2A. Next, the black block 210 moves on the white frame 220 as shown in FIG. 2B. In addition, the electrical lines distorted near the slit 118 and the protrusion 124 (shown in FIG. 3) cause the liquid crystal molecule 132 nearby to have different tilt direction from that of liquid crystal molecule 132 in other areas. Consequently, when electric field changes or the picture changes (that is, the black block 210 shown in FIG. 2B moves), the liquid crystal molecule nearby is not able to be polarized to a stable state, thereby generating a dynamic crosstalk, which results in an image-dragged white area 230 shown in FIG. 2B.